Long term longitudinal studies are uniquely valuable for the investigation of mental health and mental disorders. However, due to the difficulties encountered in conducting such studies, only a relatively few are carried out. Because this kind of research requires such a great investment of time and money, it is imperative that the best of these studies be thoroughly mined. This can be facilitated by making the data accessible, at the appropriate time, to investigators from outside the original research team. In order to make this possible in a systematic way, NIMH has funded Radcliffe College to establish an archive of long term longitudinal studies of mental health at the Henry A. Murray Research Center of Radcliffe College which is an active social and behavioral sciences research center and data archive with a special focus on longitudinal research. The archive is unique in that it includes not only coded, computer-accessible material, but also the original records or raw data of the studies. The funds granted for developing the Mental Health Archive have allowed the staff of the Murray Center, along with a distinguished advisory committee, to survey the field of longitudinal studies comprehensively, choose those studies most worthy of archiving, acquire and process the data from 15 of those studies, facilitate the use of the data sets for ambitious new research, gain permission to archive another set of important studies over the next three years, and create an updated and expanded inventory of longitudinal studies in the United States. A final grant of three years would allow the center to acquire and process 8-11 of the remaining studies that are available for archiving, complete the processing of several data sets not fully processed during the current grant period, continue to publicize the availability of the data, and promote new research based on the longitudinal data available through the Murray Center's Mental Health Archive.